Hammock



FIG. 1 is a front elevational view of the hammock of my new design;

FIG. 2 is a rear elevational view of my new design;

FIG. 3 is a side elevational view as seen from one side of my new design; and

FIG. 4 is a side elevational view as seen from an opposite side of my new design to that shown in FIG. 3. 

The ornamental design for a hammock, substantially as shown and described. 